An optical nitrite sensor based on organically modified sol-gel film has been prepared by the sol-gel method. The organic-inorganic silicate hybrid material containing encapsulated phenosafranine dye molecules was prepared by hydrolyzing and co-condensing tetraethoxysilane with the methyltrie-thoxysilane as an organically modifid sol-gel precursor, and deposited onto microscope slide glass to form a thin film via a spin-coated method. The sol-gel film presents a color changes from red to transparent when the nitrite ion reaction with phenosafranine doped sol-gel film in the acidic medium,causing decreased absorbance of the sol-gel film at 524 nm. The experimental results show that the organically modified sol-gel film has a good linear response to nitrite in the range of 0.1-1000 mg/L (r=0. 9904). The detection limit for nitrite was found to be 9 μg/L(S/N=3), and the relative standard deviation for 1.0 mg/L of nitrite was 3.4％ (n=7). The recoveries for the determination of nitrite in water samples were from 99.3％ to 104.0％.%利用溶胶-凝胶法,研制出基于有机改性溶胶-凝胶膜的亚硝酸盐光学传感器.以甲基三乙氧基硅烷为有机交联剂,与正硅酸乙酯进行水解和缩聚,制备了酚藏花红包埋的有机-无机硅酸盐杂化材料,并采用旋涂法将其涂抹在显微镜载玻片上,形成薄膜.在酸性条件下,NO<'-><,2>与酚藏花红掺杂的溶胶-凝胶膜发生作用,使溶胶-凝胶膜从红色变为无色,薄膜在524 nm处的吸光度降低.实验表明:有机改性溶胶-凝胶膜对0.1～1000 mg/L亚硝酸盐具有良好的线性响应,r=0.9904;检出限为9μg/L(S/N=3).对1.0mg/L亚硝酸盐溶液平行测定7次,相对标准偏差为3.4%,将溶胶-凝胶膜用于水样中亚硝酸盐的测定,回收率为99.3%～104.0%.
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